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p 20, 1955 c. H. COLLINS ET AL HIGH OUTPUT DUAL 0011, IGNITION SYSTEM Filed Nov. 18, 1952 Ihwentors (limnoll HIGH ourrur DUAL con roNrrioN SYSTEM Clifford H. Collins, San Gabriel, and Frank J. Pommer, Temple Qity, Califi, assignors to Harman and Collins, Inc Los Angeles, Calili, a corporation of Caiifornia Application November 18, 1952, Serial No. 321,135

7 Claims. (Cl. 24190-21) This invention relates to automotive ignition systems and deals more particularly with twin or dual ignition systems.

In conventional single-coil ignition systems for eight cylinder engines, due to the fact that for each 90 of rotation of the crankshaft of such engines, a spark is produced in one of the eight spark plugs of the engine, there is lack of time to allow for buildup of high voltage in the secondary of the coil, particularly at high engine speeds. Thus, at 1600 R. P. M. of the crankshaft, the single coil must deliver about one hundred and seven sparks per second or a total of sixty four hundred and twenty sparks per minute. At best, such single-coil ignition systems are marginal in secondary voltage output.

Recognizing the faults of single-coii systems, two-coil systems have been designed to bring current to the coils alternately and, thereby, halve the number of electric charges put out by each coil. Thus buildup of voltage in the secondary of each coil occurs through each 180 of engine crankshaft revolution and the time for such buildup is doubled over single-coil systems.

However, in order to obtain maximum performance of a two-coil system, it is not enough to merely conduct the alternate discharges of the two coils to the spark plugs through the conventional rotor and distributor cap provided with the usual slip ring to furnish the secondary contact. In such prior devices, both the primary and secondary circuits were made in the same space or chamber of the distributor cap resulting in an ozone concentration that deleteriously affected the contacts and terminals, and electrical leakage resulting from proper interposition of insulation between said circuits.

it is, therefore, an object of the present invention to provide a novel distributor for a two-coil ignition system in which the terminals and contacts are so relatively arranged that the secondary circuit is electrically remote from the metal parts of the distributor housing, the concentration of ozone around said metal parts is reduced to thereby reduce corrosion, substantial and effective insulation is interposed between the secondary and both the primary of the distributor and of said distributor parts, and provide simple means for the leads of the primary circuit.

A more specific object of the invention is to provide a generally conventional distributor and cap with novel means replacing the conventional rotor thereof to convert the usual one-coil system to an efficient two-coil system having the advantages above enumerated.

The invention also has for its objects to provide such means that are positive in operation, convenient in use, easily installed in a working position and easily disconnected therefrom, economical of manufacture, relatively simple, and of general superiority and serviceability.

The invention also comprises novel details of construction and novel combinations and arrangements of parts, which will more fully appear in the course of the following description. However, the drawing merely shows and the following description merely describes one embodi- Patent O 2318,56 4 Patented Sept. 20, 1955 ice ment of the present invention, which is given by way of illustration or example only.

In the drawing, like reference characters designate similar parts in the several views.

Fig. 1 is a side elevational view of a distributor provided with the novel means of this invention, the latter being shown in cross-section.

Fig. 2 is a plan view of said distributor with the cap thereof removed and portions broken away for clearer illustration.

Fig. 3 is a bottom plan view of an adapter plate also shown in section and in top plan view in Figs. 1 and 2.

Fig. 4 is a diagrammatic view of the present two-coil system.

A generally conventional distributor housing 5 has an axial shaft 6 that is adapted to be rotated, by connection with lugs 7, by means driven by the crankshaft of an engine. An eight-lobe cam would ordinarily be provided on shaft 6 if the distributor is used on an eight-cylinder engine. In the present case, a four-lobe cam 8 is substituted for said eight-lobe cam. The housing 5 mounts breaker point assemblies 9 and 10 which are arranged relative to cam 8 to be opened and closed alternately by said cam, the points 11 of assembly 9 and the points 12 of assembly 10 opening and closing once for each of rotation of cam 8, and the points 12 being closed when the points 11 are open and vice versa. To this end, the actuators 13 of the assemblies 9 and 10 include between them an angle of so that when one actuator is on one lobe of the cam, the other is midway between two of said lobes, and upon 45 of rotation of the cam, the operative positions of the actuators will be reversed.

Distributor housing 5 is also used for mounting condensers l4 and 15. As shown, a lateral projection 16 of said housing mounts a bracket 17 and said bracket, in symmetrical arrangement, carries said condensers.

A generally conventional distributor cap 18 is provided, the same having a central terminal 19 and a set of peripheral terminals of which only two diametrically opposite terminals 20 and 21 are shown. For an eight cylinder engine, eight such peripheral terminals are provided in cap 18, each being connected to a spark plug of said engine, as exemplified by plugs 22 and 23, respectively connected by conductors 24 and 25 to terminals 20 and 21.

According to the invention, shaft 6 mounts a novel rotor 26, and an adapter plate 27 is interposed between housing 5 and cap 18.

Rotor 26 comprises a dielectric body 28 that has a hollow downwardly directed boss 29 in keying engagement with the upper end 30 of shaft 6, and a circular plate or flange 31 residing interiorly of cap 18 to divide the interior of said cap into an upper chamber 32 and a lower chamber 33. The diameter of plate 31 is made to be slightly less than the internal diameter of the cap to obviate physical engagement of said plate and cap. By this arrangement, plate 31 constitutes an effective dielectric barrier between chambers 32 and 33.

On the upper side of plate 31 there is carried a radially disposed conductive member 34 and a diametrically opposite similar member 35, said members being aligned with the terminals of cap 18, spaced slightly therefrom, and adapted to carry electric current to said terminals successively during rotation of the rotor. As shown, member 34 is electrically connected to central terminal 19 by a resilient brush 36. A metal eyelet or rivet 37 connects member 35 with a brush 38 that extends downwardly from the under side of plate 31. It will be noted that an upstanding tubular flange 39 is provided on the rotor to form an electrical barrier between member 35 and said terminal 19 and brush 36, a depending boss 40 on the cap cooperating with flange 39 to this end. Because of the opposite locations of members 34 and 35 and the barrier formed by flange 39 and boss 40, said two members are effectively insulated and separated to obviate one said member being influenced by high voltage carried by the other. Electrical leakage from one to the other is thereby substantially eliminated.

Adapter plate 27 is formed of dielectric material and comprises a peripheral tubular part 41, a transverse plate part 42, and a central upstanding boss 43 that has a central opening 44 through which, with little clearance, boss 29 of the rotor extends. Thus, plate part 42 and boss 43 constitute a dielectric barrier between chamber 33 and the interior of housing in which the breaker point assemblies 9 and it) are disposed. Chamber 45 beneath plate part 42 forms an upper extension of the housing interior.

A metal slip ring 46 is disposed on the upper surface of boss 43 in position to be engaged by brush 38 of the rotor. A metallic radial extension 47 is connected to ring 46 and ends in a terminal 48 in the end of a radially extending dielectric arm 49 of adapter plate 27.

Adapter plate 27 is further provided with opposite lateral extensions 50 and 51 in which are disposed bus bars 52 and 53, respectively, the latter extending into chamber 45 so as to be disposed above breaker point assemblies 9 and 10. As shown in the wiring diagram of Fig. 4, bus bar 52 is connected to assembly 9 by a conductor 55 and bus bar 53 is similarly connected to assembly by a conductor 56. The binding screws 54, shown in Fig. 3, connect conductors 55 and 56 to the inner ends of the respective bus bars 52 and 53. The outer ends of said bus bars, by means of binding screws 57, are connected to condensers 14 and by respective conductors 58 and 59.

Conventional spring catches 60 connect the cap 18 to housing 5 with adapter plate 27 sandwiched therebetween. The adapter plate 27 and cap 18 are held non-rotationally relative to housing 5 by keys 61 and slots 62 where said parts join.

The above-described distributor is connected to two similar induction coils 63 and 64 and to a source of electric current 65, in the following manner:

The respective primary windings 66 and 67 of said coils receive direct current from battery 65 by means of a conductor 63 in which the usual ignition switch 69 is provided. Said primary windings are respectively connected to the binding screws 57 of bus bars 52 and 53 by conductors 70 and 71. Since said bus bars, in turn, are connected to breaker point assemblies, two independent primary circuits are provided, said circuits being alternately closed by cam 8 under control of breaker points 11 and 12.

The respective secondary windings 72 and 73 of coils 63 and 64 are connected by conductors 74 and 75 to the respective terminals 19 and 48.

Referring more particularly to Fig. 4, a spark is produced in plug 22, as follows:

Current from battery 65 is carried by conductor 68 to primary winding 66, thence through conductor 70, bus bar 52, and conductor 55 to breaker point assembly 9. This circuit is completed when points 11 are in contact because battery 65 and said assembly are both grounded. The current flowing through primary 66 produces a magnetic field in coil 63. When cam 8 opens points 11, this current ceases to flow, causing a collapse of the magnetic field and produces a high voltage charge in secondary winding 72. This charge, by means of conductor 74, terminal 19, brush 36, member 34, terminal 20, and conductor 24, produces a spark in the spark gap of plug 22.

At the time that points 11 are opened to produce the spark in plug 22, the points 12 (which had been open) close to cause a similar energization of primary winding 67 of coil 64, and then open to cause a similar collapse of the magnetic field of said coil, and a similar discharge across the gap of plug 23 of the high voltage charge produced in secondary 73. However, in this case, the

secondary charge of winding 73 passes through conductor 75, terminal 48, slip ring 46, brush 38, member 35, terminal 21, and conductor 25 to plug 23.

The above circuits function alternately and follow independent paths to plugs 22 and 23. Because of the great rapidity with which the successive sparks are produced, the manner in which the successive and alternate discharges of the two secondary windings are electrically shielded from each other by the construction of the rotor 26 and adapter plate 27, the objects of the invention are fully realized. Particularly, it will be noted that the primary circuit is confined to chamber 45 and the two secondary high voltage circuits are confined to chambers 32 and 33, respectively. Although member 35 of the secondary circuit that is confined to chamber 33 resides in chamber 32, the same is effectively shielded from the other secondary circuit by the means 39 and 4-0, as before described.

While the invention that has been illustrated and described is now regarded as the preferred embodiment, the construction is, of course, subject to modification Without departing from the spirit and scope of the invention. It is, therefore, not desired to restrict the invention to the particular form of construction illustrated and described, but to cover all modifications that may fall within the scope of the appended claims.

Having thus described the invention, what we claim and desire to secure by Letters Patent is:

1. In a distributor having two breaker point assemblies disposed within the housing of said distributor and alternately opened by the lobes of a four-lobe cam on a rotating shaft of said distributor, the improvement that comprises a dielectric adapter plate across the housing to enclose said assemblies and define a lower chamber in which said assemblies and cam reside, two spaced bus bars carried by said adapter plate and extending into said chamber, said bus bars and assemblies being adapted to be connected to the respective primary windings of two induction coils, there being a central opening in said adapter plate, a dielectric rotor connected to said shaft and having a boss extending through and substantially filling the opening of the adapter plate, a circular plate on said rotor above and in spaced relation to the adapter plate, a dielectric distributor cap mounted on the adatper plate and enclosing the rotor to define an intermediate chamber between the adapter plate and the rotor plate and an upper chamber between said rotor plate and said cap, said cap having a set of peripheral terminals and a central terminal, a conductive member carried by the rotor plate adjacent its edge and residing in the upper chamber to electrically connect said central terminal with the peripheral terminals successively during rotation of the rotor, a second conductive member carried by the rotor plate adjacent its opposite edge and aligned with the first member to also electrically connect with said peripheral terminals successively, a brush connected to said second conductive member and depending from the rotor plate into the intermediate chamber, a slip ring engaged by said brush and mounted on the adapter plate, and a terminal on said slip ring, said central terminal of the cap being adapted to connect to the secondary winding of one induction coil and said slip ring terminal being adapted to be connected to the secondary winding of the other induction coil.

2. In a distributor having a generally conventional opentopped housing provided with a rotating cam shaft and with two breaker point assemblies operated by the cam on said shaft, said distributor having a generally conventional distributor cap provided with a central terminal and a set of peripheral terminals, the improvement that comprises, a dielectric adapter plate interposed between the distributor housing and the distributor cap, and having a central opening, a dielectric rotor mounted on the cam shaft and comprising a boss extending through and substantially filling the opening in the adapter plate, and a transverse plate between said adapter plate and the closed end of the cap and substantially spanning the interior of the cap, there being a lower chamber defined between the housing and adapter plate, an intermediate chamber defined between the adapter plate and the rotor plate, and an upper chamber defined between the rotor plate and the top of the cap, two spaced bus bars carried by the adapter plate and extending into the lower chamber and adapted to connect said breaker point assemblies to the primary windings of two respective induction coils, two oppositely disposed conductive members carried by the rotor plate in operative relation to the peripheral terminals of the cap and residing in said upper chamber, a connection between one said member and the central terminal of said cap, a laterally extending terminal on the adapter plate, and means to connect the other conductive member and said latter terminal comprising a slip ring carried by the adapter plate and residing in the intermediate chamber, a connection between said ring and said lateral terminal, and a brush connected to said other conductive member and slidingly engaged with the slip ring, said central and lateral terminals being adapted to be connected to the respective secondary windings of said two induction coils.

3. In a distributor, in combination, a non-rotational dielectric adapter pulate having a central opening; a dielectric rotor having a boss extending through and substantially filling said opening and provided with a transverse plate spaced from the adapter plate; a first conductive member on the side of the rotor plate away from the adapter plate to receive and distribute secondary current from one induction coil; means to receive secondary current from a second induction coil comprising a second conductive member on said side of the rotor away from the adapter plate and spaced from the first conductive member, a brush connected to said second conductive member and directed toward the adapter plate, and a slip ring on the latter plate and slidingly engaged by said brush and a pair of spaced bus bars carried by the adapter plate on the side thereof away from the rotor plate to receive and conduct primary current of said two respective induction coils.

4. In a distributor having two alternately opened and closed breaker point assemblies, a dielectric adapter plate, a slip ring on one side of said plate and a laterally extending terminal for said ring to carry high voltage secondary current to said ring, and a pair of spaced bus bars on the opposite side of said plate to carry low voltage primary current from two separate induction coils to said two alternately opened and closed breaker point assemblies of said distributor.

5. In a distributor, in combination, a non-rotational dielectric adapter plate having a central opening; a dielectric rotor having a boss extending through and substantially filling said opening and provided with a transverse plate spaced from the adapter plate; a first conductive member on the side of the rotor plate away from the adapter plate to receive and distribute secondary current from one induction coil; and means to receive secondary current from a second induction coil comprising a second conductive member on said side of the rotor away from the adapter plate and spaced from the first conductive member, a current-conducting member connected to the second conductive member and disposed in the space between the transverse plate of the dielectric rotor and the adapter plate, and a third conductive member carried by said adapter plate in electrical engagement with said current-conducting member.

6. In a distributor having two breaker point assemblies disposed within the housing of said distributor and alternately opened by the lobes of a four-lobe cam on a rotating shaft of said distributor, the improvement that comprises a dielectric member across said housing to enclose said breaker point assemblies and define a first chamber in which said assemblies and cam reside, means entering said chamber to connect the primary windings of two induction coils to said breaker point assemblies, respectively, there being a central opening in said member, a dielectric rotor connected to said shaft and having a central boss extending through said central opening, a dielectric plate on said rotor in spaced relation to and on the side of the dielectric member away from the mentioned chamber, a dielectric cap on the side of the rotor plate opposite to the dielectric member and, together with said member, enclosing said plate, there being an intermediate chamber defined between the rotor plate and the dielectric member and a third chamber between said cap and rotor plate, said cap having a set of terminals arranged in a circle around the axis of rotation of the shaft and rotor and a single terminal Within the circle of said set of terminals, a conductive terminal carried by the rotor and residing in the third chamber to electrically connect said single terminal with the set of terminals, successively, during rotation of the rotor, a second conductive member carried by the rotor and also residing in the third member to also electrically connect with the set of terminals successively, a current-conducting member connected to the second conductive member and disposed in the intermediate chamber, and a third conductive member fixedly carried by the dielectric member and in electrical engagement with the current-conducting member, said single terminal of the cap being adapted to connect to the secondary winding of one induction coil, and said third conductive member being adapted to be connected to the secondary winding of the other induction coil.

7. In a distributor, a dielectric housing having opposed spaced end Walls and provided with a set of terminals arranged in a circle, there being a central opening in one of said walls, a dielectric rotor in the space between said walls and, in part, extending into said opening, said rotor defining two chambers between itself and said end walls, means to conduct high-tension current to said set of terminals, successively, and comprising a contact on one side of the rotor and residing in one chamber, and a current-conducting terminal engaged with said contact and carried by the housing end wall that defines said chamber, and a contact on the same side of the rotor, a terminal carried by the housing end wall that defines the other chamber, and a conductive member electrically interconnecting said latter contact and terminal and residing in said other chamber, said two mentioned contacts being aligned with and in electrically conductive engagement with said set of terminals.

References Cited in the file of this patent UNITED STATES PATENTS 1,120,112 Wright Dec. 8, 1914 1,262,544 Moses Apr. 9, 1918 1,825,720 Fitzsimmons Oct. 6, 1931 2,048,860 Guzill et al. July 28, 1936 2,163,843 Lansing et al. June 27, 1939 2,243,269 Von Faull May 27, 1941 FOREIGN PATENTS 592,270 Germany Feb. 5, 1934 

